battery charge after charge...
 

hey,

basically i have a 9.6v 1700mah NiCD battery and an overated TLP 4000C cahrger. now the following question can apply to all batteries.

basically, i want to know how come after my charger beeps telling me that it has fully charged after i fast charge it, i can then charge it again for a while. i mean, if it is charged shouldnt it beep again telling me the battery has reached its full charge just a short while after recharging it?

As a Ni-Cad battery is charged its voltage increases.

alot of nicd chargers detect a full state by watching for the point where the voltage levels off, or peaks. Some chargers go into a trickle charge state after it detects a full state, that might be what its doing.

Its also harder to tell if a nicad is full after the peak is hit (a kind of...if you blink you'll miss it kind of deal), because its not looking for a certain voltage, its looking for a change in the rate of voltage change. Li-ion batteries and their associated circuitry are alot more intelligent.

Yeah, most chargers will try to charge about 100 mah or so, to help it figure out the state, regardless of the state. If I was you, I would time it, to see how long this period is, so you know if a battery really is charged or not.

well like Zyre pointed out, my charger does the trickle charge after it peaks...

hey Rat,
I use one of those fussy logic chargers and after i give it the full charge...if i disconnect and reconnect...it tries to charge for like 3 secs then beeps to tell me its full....dont know if its a help but its kinda relevent...didnt stop my friggen batt running out at 10:30 last night...i was a trigger happy pappy
nice meeting you

What you're getting is known as a false peak. Some modern chargers will allow you to set the peak detection anywhere from as low as 3 mV/cell to 25 mV/cell or so, depending on the cell chemistry you're charging. NiCds have a higher peak than NiMHs do and are more tolerant to overcharging.

This could also be the result from fast charging at too high a current. How many amps are you charging at?

charging usually at 2 amps, but also tested at 2.5 with same result.

once again, the batt is a 9.6v 1700mah NiCD

Hmm, hard to tell what the charger's thinking since there's no readout. Maybe try charging at 1 amp and see if that helps?

will give it a shot...cant hurt... :)

Does that work?Have you got any solution for this.

I have exactly the same charger.This is what i usually do.
When the charger beeps telling me that it has fully charged after i fast charge it,i will usually fast charge it again for a while (30-45 minutes using 110mAh)to make sure it is fully charged.Since there is no readout in this charger,I am not sure if i over charged the battery or not.
I find out that the battery would last longer if i do this additional step after the charger telling me the battery is fully charged.

Am i doing something wrong here?Is overcharging really bad for batteries.

ps:all of my batteries are nicd.

i charge it a couple of times...each time the beeps getting sooner and sooner...usually charge it 3 times, each time lowering the setting. i also feel when the batt gets warm. anyway when i play i rarely just run around spraying and praying. i am not even close to ever using up the whole battery charge imo.